Legal guilt was never demonstrated, but it feels very odd for me to see the obituary continue on with such a celebratory tone after mentioning that he was arrested on child pornography charges.
I am not sure how to interpret your sense of "oddity":
if somebody is investigated for something, it does not mean they did it. The grounds to conduct an investigation are not necessarily good. Innocent until proven differently.
You understand that some may find deeply disturbing that an employer ceased the relation because of «deeply disturbing» charges.
Anyone can be subject to error or defamation.
I read on these pages recently about Chris Avellone. Supposing it was a case of gratuitous defamation out of "I thought he was different" etc., what is the responsibility of the company which dismissed him?
Most likely Mr. Shanahan's obituary had been written years ago and updated for recent events that happened to him and his family (his arrest, his son's crime).